Laser photochemical ablation of CdWO4studied with the time‐of‐flight mass spectrometric technique
作者:
Katsumi Tanaka,
Takaaki Miyajima,
Natsuki Shirai,
Quan Zhuang,
Ryohei Nakata,
期刊:
Journal of Applied Physics
(AIP Available online 1995)
卷期:
Volume 77,
issue 12
页码: 6581-6587
ISSN:0021-8979
年代: 1995
DOI:10.1063/1.359067
出版商: AIP
数据来源: AIP
摘要:
Pulsed laser ablation of CdWO4at 266 nm is studied with a quadrupole mass spectrometric (QMS) time‐of‐flight method. Ablation threshold, energy distribution, and angular distribution of the ablated species as well as nonlinearity of the ablated species mass intensity are elucidated as a function of laser fluence. Ablated species of O+2, Cd+, Cd2+, W+, and WO+translate with energies strongly depending on the fragment mass, meaning that they are confined in a space with the same velocity distribution. Ablated species detected with the QMS filament off show a Gaussian distribution for their translation energy, which is interpreted by the Franck–Condon electron excitation mechanism. A simple model is proposed based on a photochemical bond breaking to explain the observed threshold and nonlinearity of the ablated species. Nonlinearity can be explained by photofragmentation of CdWO4cluster ions and the successively occurring volume expansion. The latter will be the main cause for the desorption of ion species by ablation and supports the narrow angular spreading of the ablated species. ©1995 American Institute of Physics.
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